30 
CACTACEiE. 
These areolae in the specimen before us are 8 lines long by 4 wide, and only \ inch distant 
from one another. In some specimens of E. Wislizeni the same closeness is observed, while in 
others, especially young and vigorously growing ones, they ai;e often over one inch distant. 
The four principal central spines are 2-2| inches long, lateral ones more quadrangular, the 
upper and lower ones flat and flexible; tbe former carinate above, the latter below. This lower 
one is rather the longest and l-|-lf lines broad, almost straight or somewhat curved, but never 
(in the specimens brought home) hooked. The other spines are H-2 inches, the lowest are 
only about 1 inch long. Five radial spines are arranged below the four central ones and three 
to five above, three of which are often pushed into the centre by the flexuous bristly spines 
which occupy the space between the upper and lower radial ones and the uppermost part of the 
areola. 
At the upper end of the areola, and between it and the floral areola, we meet with the same 
obtuse eylindric ligneous (when young, fleshy) glands which divide the spiniferous from the 
floral areolae in several of our species of Echinocactus, 3-5 in number in the species before us, 
about one line long. 
We had the good fortune to collect a single specimen of the fruit, (the only one found,) 
which is globose, f inch in diameter, and, together with the persistent remains of the flower, 
about 2 inches long. Dr. Le Conte has noticed “a crown of yellow fruits on the plant, about 
2 or 2| inches long.” The dissection of the dead flower indicates a structure very similar to 
that of E. Wislizeni; petals apparently fleshy and narrow; stamina numerous, very few from 
the base, the majority from the middle and the upper thickened end of the short tube; style 10 
lines long, divided nearly down to the middle into 14 sub-erect filiform stigmata; seed black, 
oblique-obovate, compressed, carinate on lower part of back, somewhat shining, and very lightly 
pitted, (under the gla^s,) 0.8-0.9 lines long; hilum small, oval; albumen rather small; 
embryo ovate, straight, with short hooked cotyledons. Mr. Schott has found this species 
abundantly in Western Sonora and the Gadsden purchase. The flowers are yellow, and similar 
to those of E. Wislizeni, but ratber smaller; the stems are generally much higher and thick, 
and of a clavate shape; lower central spine sometimes almost hooked. 
Echinocactus Wislizeni is distinguished by the less flattened, less flexible, stouter spines, the 
lower central one being channelled above and strongly hooked; by having only three lower 
radial spines, &c. The distinction indicated by the spines is confirmed by the shape and 
structure of the seeds ; and thus the plants of the Colorado and of the Rio Grande are distinct 
representatives of the same type on both sides of the Rocky mountains. 
4. E. Wislizeni, Englm. in Wisl. Rep., (PI. Ill, fig. 1-2.)—This plant is very abundant in 
the neighborhood of El Paso, where it was first found, many years ago, by Dr. Wislizenus. 
The fruit and seed of this plant were collected by Captain Whipple in the neighborhood of 
the Cereus giganteus, while engaged in surveying the Gila, on the boundary commission, in 
1852. There possibly may be some doubt about its growing in that region, however, from the 
fact that Captain Whipple’s fruits were labeled “ Cereus giganteus,” and were not collected by 
a botanist. 
In our present expedition, when I first found a giant Echinocactus — E. Le Contei —at Cactus 
Pass, I was sure, in common with Drs. Parry and Le Conte, that it was E. Wislizeni, which I 
had often seen before at Dona Ana. I was most happy, however, in being able to secure even 
a single specimen of the fruit and seeds of that plant, by means of which, with the spines I 
collected, it has been identified and confirmed by the acute observations of my friend, Dr. Engel- 
mann. It may be well to observe here, that the figure of this plant, in Major Emory’s report, 
was made from a specimen seen on the headwaters of the Gila, near the mouth of the Azul 
branch, not far from Sauta Rita del Cobre, or Copper Mines, and at least four degrees of 
longitude east of the place where first met Ech. Le Contei. 
